example.md

module "ekscluster" {
  source="git::https://github.com/polganesh/terraform-aws-eks-cluster.git"
  region      = "eu-central-1"
  region_id   = "euc1"
  cost_centre = "infra"
  vpc_seq_id  = "001"
  seq_id      = "001"
  environment = "n"
  app_service = "demo"
  # these are EKS optimized images more information about ami id based on k8s cluster and region at
  # https://docs.aws.amazon.com/eks/latest/userguide/eks-optimized-ami.html
  image_id         = "ami-0f64557dd6506a4aa"
  key_name         = "poc-key"
  desired_capacity = "10"
  min_size         = "1"
  max_size         = "10"
  # it supports X.xx but does not support X.xx.x  
  eks_version                              = "1.14"
  inbound_cidr_rules_for_workstation_https = [["XX.XX.XX.XX/XX", "mylocalIP"]]
  control_plane_logging_to_be_enabled      = ["api", "authenticator", "controllerManager", "scheduler"]
  worker_node_instance_types = [
    {
      "instance_type" = "t3a.medium"
    },
    {
      "instance_type" = "t3.medium"
    },
    {
      "instance_type" = "t2.medium"
    },
    {
      "instance_type" = "t2.micro"
    }	
  ]
  # 0% has to be on on_demand instances for base capacity
  worker_node_on_demand_base_capacity = "0"
  #40 percent above base capacity has to be run on on_demand instances 
  worker_node_on_demand_percentage_above_base_capacity = "40"
  # it is used for running spot instances else capacity-optimized
  worker_node_spot_allocation_strategy= "lowest-price"
  worker_node_spot_max_price="0.030"
}

output "kubeconfig" {
  value = "${module.ekscluster.kubeconfig}"
}


output "config_map_aws_auth" {
  value = "${module.ekscluster.config_map_aws_auth}"
}

This will enable 6 instances to be SPOT while 4 instances on demand instances.